Continuously revolving percussion drilling machine

Abstract

Continuously revolving percussion drilling machine, which comprises a body (1), a drill shank (2) mounted rotatably and axially slidably in the body for causing impacts on the drill rod, an impact mechanism (3) positioned in the body for causing axial impacts on the drill shank, and a rotating device (4) for rotating the drill shank around its axis. The drill shank is provided with a toothing (8), which is coupled in direct engagement with a toothing (9) revolving in relation to the drill shank and rotating the drill shank, said toothing of the drill shank being axially displaceable in relation to said rotating toothing, so that the contact surfaces of the teeth of the toothing on the drill shank and of the toothing rotating the drill shank revolve and are exchanged constantly. The teeth operate cold and well lubricated. The rotating toothing may be a cogwheel or a tooth rim.

What is claimed is: 
     
       1. A continuously revolving percussion drilling machine, comprising: a body;   impact means positioned within the body, said impact means causing axial impacts on a drill shank,   the drill shank mounted rotatably and axially slidably within the body and causing impacts on a drill rod,   rotating means for rotating the drill shank about a longitudinal axis thereof,   the drill shank having a helical toothing for direct and rotatable engagement with a helical toothing of said rotating means,   the toothing of said rotating means continuously revolving and making complete revolutions in relation to the drill shank, the drill shank toothing extending away from said impact means and inclined with respect to the axial direction of impact in a direction opposite from the direction of rotation whereby contact between the toothing of the drill shank and the toothing of said rotating means are substantially reduced during impact movement of the drill shank.   
     
     
       2. A continuously revolving percussion drilling machine as claimed in claim 1, characterized in that the toothing (8) of the drill shank (2) is in engagement with a toothing (9) of a cogwheel (6, 7), which is directly or indirectly coupled to said rotating means (4). 
     
     
       3. A continuously revolving percussion drilling machine as claimed in claim 1, characterized in that the toothing (18) of the drill shank (2) is in engagement with a toothing (19) of a tooth rim (17), said tooth rim being rotatingly mounted in the body of the drilling machine and being positioned around the drill shank, which tooth rim is directly or indirectly coupled to said rotating means (4). 
     
     
       4. A continuously revolving percussion drilling machine as claimed in claim 3, characterized in that the tooth rim (17) is a part of the rotating motor. 
     
     
       5. A continuously revolving percussion drilling machine as claimed in claim 1 further including means for directly rotatably driving said rotating means. 
     
     
       6. A continuously revolving percussion drilling machine as claimed on claim 5 wherein said means for directly rotatably driving is an electric motor.